Recently, user terminals having cellular communication and wireless local area network (LAN) communication (so-called dual terminals) have become widespread. In addition, the number of wireless LAN access points managed by an operator of a cellular communication system is on the rise.
Thus, in the 3rd Generation Partnership Project (3GPP), which is a standardization project for a cellular communication system, there has been considered a technique that can strengthen cooperation between a cellular radio access network (RAN) and a wireless LAN.
For example, by switching a network so that the traffic of a user terminal that is accommodated in a cellular RAN is accommodated in a wireless LAN, the traffic load on the cellular RAN can be reduced (off-load).
In addition, as a network selection scheme for selecting, from the cellular RAN and the wireless LAN, an access network in which the traffic of a user terminal is accommodated, a plurality of network selection schemes is proposed (refer to Non Patent Literature 1).